Method of operating brakes



May 11 1926. 1,584,3(53

T. M. FRE-EBLE METHOD OF OPERATING BRAKES Filed March 25, 1925 msg v w o3 g/X I INVENTOR Patented May 11, 1926,

srres THOMAS M. FREEBLE, OF ROCHESTER, PENNSYLVANIA, ASSIGNOR OFONE-HALF TO r'rrur CARL SGI-IUSTER, F PITTSBURGH, PENNSYLVANIA.

METHOD OF GPERATING- BRAKES.

Application filed March 25, 1925. Serial No. 18,129.

The present invention relates to methods of operating brakes on'railwaytrains, and is particularly adapted-for use on trains of considerablelength, such for example, as freight trains. v

The flexibility of control of a railway train by the use of air brakesis reduced as the length of the train is increased. This is largely dueto the interval which elapses between the times of response of brakes atopposite ends of the train when the control valve in the engineers cabis set.

A particularly serious objection to the methods hitherto employed isillustrated in the case of a freight train approaching a warning signalwhich is actuated to indicate clear track just before the signal toweris reached. It frequently happens that the brakes are applied and thetrain speed is checked to a low rate before clear track is indicated.Under the present methods of operation it is necessary to completelystop the train before increasing the speed. The reason for this is thatit is impossible to release the brakes on the rear of the trainsimultaneously with or before releasing the brakes at the head of thetrain. That is, under the present methods the brakes on the rear of thetrainwould be still set when the head of the train is running free. Itis obvious then, in the example cited, that an attempt to increase thespeed of the train would result in pullingthe train apart. Because ofthis deficiency of the ordinary systems of brake control, much time islost by needlessly stopping and starting long freight trains.

I provide a method of operation which permits long trains to be slowedto a low rate of speed and then brought back to running speed withoutthe necessity of stopping and starting. This flexibility of control isobtained by releasing the brakes adjacent the rear of the train beforereleasing those adjacent the head end of the train. The releasing actiontravels sequentially from the rear of the train toward the front of thetrain at a rate depending upon the time taken to efiect a change ofpressure in the train line. It will be understood that no attempt ismade to apply the brakes in this manner because of the danger ofrupturing the train, the brakes being applied sequentially from thefront of the train toward the rear.

Figure 3 illustrates a method of valve connections which may be employedif a standard control valve is used.

Referring first to Flgure 1, there is shown an engine 2 provided with anair control valve 3 by which'the air pressure in a train line 4 or anauxiliary line 5 may be regulated. The air required for the op erationof the brakes is supplied to the control valve 3 by a line 6 from astorage tank 7 supplied by an air compressor 8.

The standard train line 4: is connected by I hose connections 9 to pipes10 on the various cars 11. The pipes 10 serve the triple valves 12connected to individual air tanks 13 on the cars 11. This is customaryequipment on railway trains.

The auxiliary line 5 is likewise connected by hose connections 14: toauxiliary pipes 15 on the various cars 11. 15 and hoses 14L constitutean independent conduit running the length of the train. At the end ofthe train the hose 9 on the standard train pipe 10 is connected to thehose 14 on the auxiliary pipe 15 thereby forming a complete air systemfrom the con trol valve 3 to the rear of the train and back to thecontrol valve'3.

The control valve 3, as illustrated diagrammatically in Figure 2, isprovided with a valve body 16 having a rotatably mounted plug 17therein. The body 16 is illustrated as having an air inlet port 18leading from the air line 6, a port 19 leading to the auxiliary line 5,a port 20 leading to the regu lar train line 4, and ports 21 and 21leading to the atmosphere. The plug 17 may be turned to any desiredposition by a handle 22. The plug 17 is provided with a passage 23 whichserves to interconnect the ports in the body 16.

If the train is long and it is desired to release the brakes, before adead stop is reached, so that the train may get under way again, thehandle 22 is turned to the position illustrated in Figure 2. Air fromthe tank 7 flowing through the passage 23 The auxiliary pipes in thevalve, is admitted to the auxiliary train line 5 and increases thepressure in the standard train pipes 10 at the rear of the train. Thetriple valves 12 then operate and the brakes are released first at therear of the train and the train closes up. Should steam then be admittedto the engine there is no danger of pulling the train apart for the rearcars are running free. Thus I provide a flexible method of operating airbrakes on long trains. One of the distinct advantages of my method liesin the fact that the brakes may be applied and released in the usualmanner if the train is short. That is, the handle 22 may be turned tothe usual positions of lap, service, release and emergency, withoutusing the auxiliary line 5.

Figure 3 illustrates a standard air control valve 24, bypassed by theauxiliary line 5 having a separate valve 25 conveniently placed therein.By this arrangement it is not necessary to have the special port 19 forthe auxiliary line 5 shown in Figure 2 in the main control valve 245,since air may be admitted to the auxiliary line 5 through the separatevalve 25 if it is desired to effect a release of brakes on the rear ofthe train prior to releasing those on the head end.

lVhile I have described my invention with reference to a particularembodiment, it will be understood that the invention is not limitedthereto, but may be otherwise embodied within the scope of the followingclaims.

I claim:

1. The method of operating a brake system on a train which comprisesreleasing the brakes sequentially from the rear of the train toward thefront of the train, substantially as described.

2. The method of operating an air brake system on a train whichcomprises supplying air progressively from the rear to the front of thetrain for the, release of the brakes, substantially as described.

3. The method of operating a brake system having a plurality of brakeoperating means and afiuid pressure line connecting said operating meanswhich com-prises releasing the brakes by first supplying fluid underpressure to the brake operating means at the rear of the train andpermitting sequential release of the brakes toward the front of thetrain by the increase of pressure toward the front of the train in thesaid fluid connecting line, substantially as clescribed. a

l. The method of operating a trainbrake system having a plurality ofbrake operating means responsive to a fluid pressure and a fluidpressure line connecting said operating means which comprisesregulatingthe pressure in the fluid pressure line to effect a sequential operationof the brake operating 7 means to release the brakes from the rear ofthe train toward the front of the train, a

substantially as described.

The method of operating a brake system on a train of coupled cars eachhaving brakes and brake operating means which comprises applying thebrakes sequentially from the front of the train toward the rear thereofto reduce the speed of the train and releasing the brakes sequentiallyfrom the rear of the train toward the front thereof to permit increasingthe speed of the train, substantially as described.

6. The method of operating a brake sys I THOMAS M. FREEBLE.

